The distributed differential mixing combined power system is used in driving the traffic machinery such as vehicles, ships, flying machines or other mechanical structures (or other industrial or process equipment)in rotational driving applications, wherein it is chiefly comprised of that the rotational output shaft of the internal combustion engine (or other rotational power sources) is not only used to drive the front section load directly or through the transmission devices such as the transmission gears, belt or chain or the couplers, but is also coupled with the input shaft of the differential mixing drive unit to drive the rear section load. The said differential mixing drive device is comprised of an electrical machine combined with a three-end shaft differential wheels transmission system which is embodied in a three-end shaft differential gears structure, wherein the two differential output shaft and a input shaft are coupled with the electrical device through a transmission gear, while the two wheel shafts of the differential gears are respectively coupled with the transmission middle shaft drived by the drive side rotational power unit and are coupled with the input shaft of the rear differential gear box through a clutch to drive the two side differential acting rear section load; wherein the above said three-end shaft differential gears system can be substituted by a planetary gear train and the transmission gear can be substituted by a friction wheel; further, a brake is installed between the rotor and the stator of the electrical machine and the said brake is controlled by the operating device to generate motor driving functions when the input current is applied or to generate the variable speed coupling functions through the output current when it is employed as a generator, or to be used for starting the engine and the power regeneration brake which is particularly for case when the engine is the main transmission power source to charge the battery through the electrical machine of the differential mixing drive device, wherein the speed difference with the rear load section can be adjusted by controlling the charging current. The said engine can be at a constant speed or at a partially adjustable speed thereby to maintain at a working speed of higher operating efficiency and lower pollution and one part of the differential speed output power generated through the differential mixing drive device is used for driving the load while the rest part of the power is converted through the generator function of the electrical machine of the differential mixing drive device to charge the battery, thereby to promote the engine efficiency in the variable speed driving at the low driving speed range, to acquire the charging power to the battery while reducing the pollution, and to provide the variable speed coupling. Besides, it can also be used as a driving motor to generate rotational output to drive the load independently or to drive the load with the engine together.